If you have any heavy packages recently installed (and are going to wipe the system for any reason), you might look into
ls -l /var/cache/apt/archives
to see which might be restored to the same place to avoid repumping them.
A quick way to see which packages are related to something is
apt-cache search java
Another less quick but more detailed, also shows what is installed on your system, is
dpkg -l '*java*'
You may see what was installed and when (for maverick)
or, less conveniently (for lucid)